Chair structure



y 1966 R. P. MOLLOY 3,250,509

CHAIR STRUCTURE Filed July 20, 1954 50 INVENTOR. RICHARD P. MOLLOY BY A!W 464mm! (dings.

United States Patent 3,250,509 CHAIR STRUCTURE Richard P. Molloy,Kalamazoo, Mich, assignor to Bruns- Wick Corporation, a corporation ofDelaware Filed July 20, 1964, Ser. No. 383,606 Claims. (Cl. 248-417)This invention relates to a chair structure or the like, and moreparticularly to a structure including a tubular upright supportcontaining mounting means for adapting the tube to carry a swivel seator the like.

It is a general object of this invention to provide a new and improvedseat assembly.

It is another object to provide a new and improved swivel chairconstructed in part from commencially available tubing of any desirablecross-sectional shape.

Another object is to provide a new and improved swivel chair having anupright tubular support which carries a tube adapter fixably secured inits upper end for rotatably supporting a seat mounted thereon.

Further objects are to provide a chair having a mounting adapter forenabling an upright tubular support on the chair to receive a swivelseat, the adapter including means for aligning the adapter inside saidtubular support and also having means for locking the adapter to thesupport; and to provide the mounting adapter with locking means in theform of a horizontally expandable element which may be expanded intoengagement with the chair with the seat portion removed and partly insection along the line 22 of FIG. 1 to show the structure used topi-vota-lly mount the seat;

FIG. 3 is an enlarged axial section view of the assembly mounting deviceprior to locking it to the seat assembly; and

FIG. 4 is a plan view of an expandable element used to lock the mountingdevice to an upright tubular support.

While a preferred illustrative embodiment of the invention is shown inthe drawings and will be described in detail herein, the invention issusceptible of embodiment in many different forms, and it should beunderstood that the present disclosure is to be considered as anexemplification of the principles of the invention and is not intendedto limit the invention to the embodimentillustrated herein. The scope ofthe invention will be pointed out in the appended claims.

Referring now to the drawings in more detail, a chair assembly showngenerally at 10 consists of a floor-engaging support or structure 12supporting an upright tubular member or support 14 having an outer wallor surface 14a, and an inner wall or surface 141) to which is afiixed atits upper end a mounting device or adapter 16 for enabling the tubularsupport 14 to rotatably carry a forwardly biased swivel seat assembly18.

The structure 12, as shown, consists of five vertical legs 20 connectedtogether at their top ends as by circular foot rest 22, each leg havinga horizontal spoke 24 directed inwardly from its midportions andconnected to the lower end of the support 14. Tubular support 14consists of an elongate tube of generally circular cross-section havingits upper portions extending vertically above pedestal L2. The lowermostend 30 of the tube is open to permit entry therein by a socket wrench,to be described more fully "ice later. It will be understood that thespecific shape of tube 14 and the manner in which it is supported at itslower portionsmay be varied considerably.

Upper edge 3-2 of the support 14 lies in a horizontal plane, and theupper inner edge of inner wall 14b is beveled as at 34 to facilitate themounting of adapter 16, as will be described hereinafter.

Adapter or mounting means 16 consists of a main hollow member 36,preferably made of die cast aluminum, having an upper horizontal annularflange 38 forming a downwardly facing horizontal shoulder 40 which restson the upwardly facing horizontal edge 32 of tubular support 14.Immediately below flange 38 of member 36 is a relatively short taper 42having an average diameter slightly in excess of the average diameter ofbevel 34 on support 14 so as to cause an interference fit therebetweenwhen shoulder 40 is moved down into contact with edge 32. Centralportions of member 36 form a sleeve that tapers downwardly to ahorizontal shoulder 44 which faces downwardly towards a reduced diameterportion 46, also on member 36, which is threaded to the lower end 50toreceive a nut 48. Mounted above nut 48, and also on the threads 46, isa vertically movable washer 52. Above washer 52, and similarly mountedfor vertical movement over threads 46 is an expandable locking orgripping element 54 having a generally three bladed propeller-like shapein plan view, as can be seen in FIG. 4. Element .54 is formed of metaland has a hole 56- .therethrough for mounting over the threaded portion46 of the adapter body 36. Element 54 also includes a plurality ofoutwardly extending and angularly spaced projections 58 having outeredges 60 adapted to engage and grip the inner wall 14b of uprightsupport 14. Projections 58 are tilted downwardly at an acute angle withthe horizontal as shown at 62 providing element 54 with an outerdiameter sufficiently small to allow its insertion into the tube 14. Aswill be described in great detail later, nut 48 may be screwed upwardlyafter insertion of the adapter 16 into the upper portion of the tube 14to urge washer 52 upwardly into engagement with projections 58 therebydriving them upwardly and into engagement with the inner surface 14b ofthe tubular support 14. It will be understood that element 54 iscompressed vertically and expanded horizontally to lock it incompressionto the support 14.

The member 3-6 of mounting adapter 16 includes an integrally cast socket64 defining a bore 66 of circular cross section therein opening upwardlyas at 68, best seen in FIG. 3. Disposed within bore 66 is a pistonassembly 7 0 including a spring 72, a follower or piston 74 above thespring and biased upwardly thereby, and a spherical ball 76 supported byand above piston 74.

Member 36 also has a centrally located bore 80 of circular cross sectionextending vertically therethrough and aligned with tube 14, bore 80being adapted to receive and support a portion of the seat assembly 18.A circula-r recess 82 of greater diameter than bore 80 is provided inthe upper surface of member 36 to form a seat for a plurality of freelyrotatable washers 84 (FIG. 2) which act as thrust hearings in rotatablysupporting the seat assembly and loads placed thereon.

Seat assembly 18 consists generally of a lower seat supporting casting86, a seat 88 mounted on casting 86 by suitable fasteners (not shown)which extend through casting 86 as at 90, said seat having an integralbottom portion 92 and backrest portion 94 (preferablyrnolded ofplastic), and, if .desired, a cushion resting on or affixed to the uppersurface of bottom portion 92 as at 96.

Casting 86 carries a shaft 98 having an upper portion 100 rigidlyembedded in casting 86, as by casting it therein, and a lower portion104 extending through the bore 80 of adapter 16, said bottom portion 104having threads 106 at its lower extremity extending below shoulder 50 ofadapter 16. A plurality of washers 168 are impaled by threaded portion166 of shaft 98, each having a. central hole 'of a diameter sufficientlylarge to slide over threads 106 but not sufiiciently large to slide overthreads 46 of adapter 16. Washers 108 are held in place by acorn nutv110 which is screwed up on threaded portion .106 of shaft 98sufficiently to take up any vertical play of shaft 98 without putting itin compression. This mounting prevents seat assembly :18 from beinglifted vertically off the support 14 but allows f-ree rotation relativethereto about its vertical axis.

Seat casting 86 also has a cam surface 112 cast into its lower surface,having a circular configuration when viewed from the bottom, and beinginclined at an acute angle from the horizontal. C am surface 112 isengaged by ball 76 of piston assembly 70 under the upward bias of spring72 which tends to rotate the sea-t toward a predetermined forwardlyfacing position, such as vfacing a table or a bar. 4

In assembling the seat structure, washers 84 are well lubricated andplaced over shaft 98 which is then also lubricated and inserted throughhole 80 of the adapter assembly 16 so as to have its threaded endportions 106 exposed below the shoulder 50 of the adapter member 36.Washers 108 are then well lubricated, placed over threaded portions 106of shaft 98, and secured in place by acorn nut 110 which is drawn up topermit relative rotation between shaft 98 and adapter 16 but preventrelative translation therebetween along their common axes. The adapter16 of the adapter and seat assembly combination is then inserted intothe upper open end of the tubular support 14 and pushed downwardlytherein to cause taper 42 on the adapter body to mate with bevel 34 onthe upper end of the tubular support 14, this taper and bevel formingupper centering means for centering the upper end of adapter body 36 inthe tube.

-An extension socket wrench is then inserted through the lower hole 30of the tube 14 so as to engage nut 48, acorn nut 100 being of somewhatsmaller diameter than the nut 48 so that the socket wrench may heslipped over acorn nut 110 so as to turn nut 48 without turning acornnut 102. Friction between bevel 34 and taper 42 prevents turning of theadapter body 36 relative to tube 14 as nut 48 is rotated. Nut 48 is thendrawn up against washer 52 which bears against projections 58 so as tobend them upwardly and outwardly forcing edges 56 into lockingengagement with the inner surface 14b of the tubular support 14. Equalspreading of extensions 58 outwardly centers the lower portions ofadapter body 36, :which, together with the upper centering means,properly aligns bore 80 with the axis of support 14.

Further tightening of nut 48 creates a downward force on member 36 ofthe adapter so as to draw shoulder 40 down into abutting engagement withupper edge 32 of the support thereby creating an interference fit between taper 42 and bevel 34. It will be understood that the adapterassembly -16 is now fixedly secured to the support 14, and seat assembly18 is free to rotate but cannot be lifted up and away from the support14. When provided with the swivel return mechanism, seat assembly 18 maybe rotated about a vertical axis and will always return to its forwardposition when released.

Although the invention is shown including a bar stool mounted on a tubeof circular cross section, it will be appreciated that the principlesdisclosed herein may be incorporated into swivel seats having supportsof various configurations and cross-sectional shapes as well as withother types of seats.

I claim:

-1. A swivel seat capable of returning itself to a forwardly facingposition, comprising: a floor-engaging support including a hollow tubeat the upper end thereof, a swivel seat mounting member carried by saidtube in its upper end having an upper flange in part resting on and in.part fitted within the upper end of said tube, a sleeve portion belowsaid flange extending downwardly within the tube and having anexternally threaded reduced portion at its lower end, said member havinga bore extending vertically therethrough, and a substantially verticalhole offset from said .bore and opening upwardly through the flange; anexpandable gripping element mounted over said threaded portion andagainst a shoulder thereabove and having a plurality of radiallyextending projections tilted slightly downwardly from the horizontal andengaging the inner wall of the tube; a washer carried by said threadedportion below said element and in contact with said projections; and anut on said threaded portion below said washer to hold said projectionsin their extended positions in locked engagement with the tube, therebysecuring said member to the tube; a seat assembly having bearing meansrotatably carried on said mounting member flange and having a dependingshaft extending through said bore, said shaft having a lower threadedportion extending below said member, a nut on the lower threadedportions of said shaft for preventing removal of said seat assembly fromsaid mounting member; said seat assembly also having a generallydownwardly facing and arcuately curved cam surface inclined in a planemaking an acute angle with the horizontal; and a compression springcarried in said hole with a generally vertically biased follower memberthereabove for exerting a force against said cam surface and biasingsaid seat assembly toward its forwardly facing position.

2. A swivel seat capable of returning itself to a forwardly facingposition, comprising: a floor-engaging support including a hollow tubeat the upper end thereof,

a swivel seat mounting member carried by said tube in its upper endhaving an upper flange in part resting on and in part fitted within theupper end of said tube, a sleeve portion below said flange extendingdownwardly within the tube and having a threaded portion at its lowerend, said member having a bore extending vertically therethrough, and asubstantially vertical hole offset from said bore and opening upwardlythrough the flange; an expandable gripping element mounted on said lowerend and having a plurality of radially extending projections tiltedslightly downwardly from the horizontal and engaging the inner wall ofthe tube; and a threaded fastener in mating engagement with saidthreaded portion and exerting a force against said elebore; means forpreventing removal of the seat assembly from the mounting member; saidseat assembly also having a generally downwardly facing and arcuatelycurved cam surface inclined in a plane making an acute angle with thehorizontal; and a compression spring carried in said hole with agenerally vertically biased follower member thereabove for exertingforce against said cam surface and biasing said seat assembly toward itsforwardly facing position.

3. A swivel seat comprising: a fioor-engaging support including a hollowtube at the upper end thereof, a swivel seat mounting member carried bysaid tube in its upper end having an upper flange in part resting on andin part fitted within the upper end. of said tube and a sleeve portionbelow said flange extending downwardly within the tube and having anexternally threaded reduced portion at its lower end, said member havinga bore extending vertically therethrough; an expandable gripping elementmounted over said threaded portion and against a shoulder thereabove andhaving a plurality of radially extending projections tilted slightlydownwardly from the horizontal and engaging the inner wall of the tube;

a washer carried by said threaded portion below said element and incontact with said projections; and a nut on said threaded portion belowsaid washer to hold said projections in their extended positions inlocked engage ment with the tube, thereby securing said member to thetube; and a seat assembly having bearing means rotatably carried on saidmounting-member flange and having a depending shaft extending throughsaid bore, said shaft having a lower threaded portion extending belowsaid member and a nut on said lower threaded portions for preventingremoval of said seat assembly from said mounting member.

4. A swivel seat comprising: a floor-engaging support including a hollowtube at the upper end thereof, a swivel seat mounting member carried bysaid tube in its upper end having an upper flange in part resting on andin part fitted within the upper end of said tube and a sleeve portionbelow said flange extending downwardly within the tube and having anexternally threaded reduced portion at its lower end, said member havinga bore extending vertically therethrough; an expandable gripping elementmounted over said threaded portion and against a shoulder thereabove andhaving a plurality of radially extending projections tilted slightlydownwardly from the horizontal and engaging the inner wall of the tube;a washer carried by said threaded portion below said element and incontact with said projections; and a nut on said threaded portion belowsaid washer to hold said projections in their extended positions inlocked engagement with the tube, thereby securing said member to thetube; and a seat assembly having bearing means rotatably carried on saidmounting member flange and having :2. depending shaft extending throughsaid bore.

5. A swivel seat comprising: a floor-engaging support including a hollowtube at the upper end thereof, a swivel seat mounting member carried bysaid tube in its upper end having an upper flange in part resting on andin part fitted within the upper end of said tube and a sleeve portionbelow said flange extending downwardly within the tube and having athreaded portion at its lower end, an expandable gripping element belowsaid lower end and having a plurality of radially extending projectionstilted slightly downwardly from the horizontal and en gaging the innerwall of the tube; a threaded fastener in mating engagement with saidthreaded portions and exerting a force on said projections to hold saidprojections in locked engagement with the tube, thereby securing saidmember to the tube; and a seat assembly having bearing means rotatablymounting said seat assembly to said mounting member.

6. A seat supporting structure, comprising: a floorengaging supportincluding a uniform upwardly extending tube; and an adapter assemblycarried in the upper and inner portions of said tube for adapting saidtube to rotatably carry a seat thereabove consisting of an elongatedbody portion, a taper near its upper end for forming an interference fitbetween said body and the inner surface of said tube, a downwardlyfacing shoulder below said tapered portions, a threaded portion adjacentsaid shoulder, an expandable element having a central hole therethroughabutting said shoulder and having a plurality of outwardly extendingangularly bent projec- .tions with end edges adapted to be pressed intolocking 6 engagement with the inner wall of said tube, a threadedfastener screwably engaging said threaded portions and locking saidexpandable element to said body; and means for rotatably supporting aseat thereabove.

7. A swivel chair structure, comprising: a lower floorengaging support;a uniform tube forming a part of said support and extendingsubstantially vertically upward therefrom; a member carried inside saidtube at its upper end having a hole extending generally verticallytherethrough and having means for centering and supporting it in saidtube; a seat assembly mounted for rotation relative to said member andhaving a shaft depending downwardly from its middle. lower portions andextending through said hole, lower portions of said shaft being threadedand extending below the bottom of said member; gripping means fixedlylocking said member to the inner wall of said tube; and other threadedmeans for engaging the threaded portions of said shaft and preventingsaid seat assembly from being lifted olf said tube.

8. A rotatable chair assembly, comprising: a supporting structureincluding an elongate upright tubular member; a seat mounting adaptermounted inside said tubular member including means for aligning saidadapter in said tube; a compression element on the adapter havingportions extending laterally into engagement with the inner surface ofsaid tube for fixedly locking said adapter to said tube; means forcreating compression in said compression element; means providing avertical bore in said adapter; and a seat structure carried by saidadapter including a depending shaft rotatably received in said bore.

9. A rotatable seat assembly comprising, in combinat-ion: afloor-engaging support including an upright hollow tube, a mountingdevice carried inside the tube at its upper end, said device havingexpandable means and means for expanding the same into contact with saidhollow tube fixahly locking the device to the tube, a swivel seatrotatably carried by said mounting device, and cooperating means forminga part of said swivel seat and mounting device for biasing said swivelseat to a predetermined position relative to said support when saidmounting device is locked to said tube.

10. In a swivel chair including an upright supporting tube and a seatthereabove, the improvement comprising: a mounting member mounted in thetube at its upper end to rotatably support said seat thereabove andincluding a hollow sleeve portion extending downwardly into said tubemeans for centering the mounting member in the tube, and means carriedby the mounting member for locking the mounting member to the tube.

References Cited by the Examiner UNITED STATES PATENTS 1,870,833 8/ 1932Burr 287-414- X 2,816,769 12/ 1957 Noble 2-87- 1 14 X 3,055,628 9/ 1962Savage 248-417 3,107,891 10/ 1963 Burke 248-417 FOREIGN PATENTS Ad.22,965 3/ 1921 France.

CLAUDE A. LE ROY, Primary Examiner,

1. A SWIVEL SEAT CAPABLE OF RETURNING ITSELF TO A FORWARDLY FACINGPOSITION, COMPRISING: A FLOOR-ENGAGING SUPPORT INCLUDING A HOLLOW TUBEAT THE UPPER END THEREOF, A SWIVEL SEAT MOUNTING MEMBER CARRIED BY SAIDTUBE IN ITS UPPER END HAVING AN UPPER FLANGE IN PART RESTING ON AND INPART FITTED WITHIN THE UPPER END OF SAID TUBE, A SLEEVE PORTION BELOWSAID FLANGE EXTENDING DOWWARDLY WITHIN THE TUBE AND HAVING AN EXTERNALLYTHREADED REDUCED PORTION AT ITS LOWER END, SAID MEMBER HAVING A BOREEXTENDING VERTICALLY THERETHROUG, AND A SUBSTANTIALLY VERTICAL HOLEOFFSET FROM SAID BORE AND OPENING UPWARDLY THROUGH THE FLANGE; ANEXPANDABLE GRIPPING ELEMENT MOUNTED OVER SAID THREADED PORTION ANDAGAINST A SHOULDER THEREABOVE AND HAVING A PLURALITY OF RADIALLYEXTENDING PROJECTIONS TILTED SLIGHTLY DOWNWARDLY FROM THE HORIZONTAL ANDENGAGING THE INNER WALL OF THE TUBE; A WASHER CARRIED BY SAID THREADEDPORTION BELOW SAID ELEMENT AND IN CONTACT WITH SAID PROJECTIONS; AND ANUT ON SAID THREADED PORTION BELOW SAID WASHER TO HOLD SAID PROJECTIONSIN THEIR EXTENDED POSITIONS IN LOCKED ENGAGEMENT WITH THE TUBE, THEREBYSECURING SAID MEMBER TO THE TUBE; A SEAT ASSEMBLY HAVING BEARING MEANSROTATABLY CARRIED ON SAID MOUNTING MEMBER FLANGE AND HAVING A DEPENDINGSHAFT EXTENDING THROUGH SAID BORE, SAID SHAFT HAVING A LOWER THREADEDPORTION EXTENDING BELOW SAID MEMBER, A NUT ON THE LOWER THREADEDPORTIONS OF SAID SHAFT FOR PREVENTING REMOVAL OF SAID SEAT ASSEMBLY FROMSAID MOUNTING MEMBER; SAID SEAT ASSEMBLY ALSO HAVING A GENERALLYDOWNWARDLY FACING AND ARCUATELY CURVED CAM SURFACE INCLINED IN A PLANEMAKING AN ACUTE ANGLE WITH THE HORIZONTAL; AND A COMPRESSION SPRINGCARRIED IN SAID HOLE WITH A GENERALLY VERTICALLY BIASED FOLLOWER MEMBERTHEREABOVE FOR EXERTING A FORCE AGAINST SAID CAM SURFACE AND BIASINGSAID SEAT ASSEMBLY TOWARDS ITS FORWARDLY FACING POSITION.